AS-C202

Background Knowledge：

New materials for sealing structure and its new production processes

(1) Soft sealing  ring materials: The soft sealing ring materials for mechanical seals have been developed from ordinary impregnated resin/metal graphite and other reinforced graphites to silicide graphite, vapor deposited carbon graphite, BN reinforced graphite, carbon-carbon composite materials, etc.  

(2) Hard sealing ring materials: The hard ring materials for mechanical seals have been developed from cast iron, Al2O3 ceramics, and cemented carbide to SiC and CrC with excellent comprehensive properties. Deposition of wear-resistant layer (such as DLC film) on friction surface, laser cladding, thermal spraying ceramics, thermal spraying nickel-based self-fluxing alloy/thermal spraying iron-based self-fluxing alloy, thermal spraying ceramic/thermal spraying iron-based coating and other technologies are adopted to reduce costs and obtain cost-effective mechanical seal basic parts.

(3) Auxiliary sealing ring materials: In addition to traditional rubber-like materials, ordinary reinforced PTFE composite materials and flexible graphite，various micro-nano-scale particles， fibers and new resins are added in the above-mentioned matrix materials in the past 20 years to develop new auxiliary sealing ring materials for mechanical seals. And  through the application of new surface treatment technology and method to treat the surface of the filler, the compatibility between the filler and the matrix material is greatly improved, thereby improving the mechanical properties, thermal properties and friction properties of traditional rubber and plastic materials, so that the performance stability, wear resistance and durability of the sealing ring far exceed the original rubber-plastic auxiliary sealing ring. In addition, resin materials such as polyetheretherketone (PEEK), ultra-high molecular weight polyethylene (UHWPE), polyphenylene sulfide (PPS), polyoxymethylene (POM), and perfluororubber (FFKM) and fluoroplastic covering rubber used as new sealing materials have been successfully applied.